U.S. patent application number 11/885046 was filed with the patent office on 2009-04-23 for puncture device.
This patent application is currently assigned to Terumo Kabushiki Kaisha. Invention is credited to Katsuaki Soma, Satoshi Wada, Hiroshi Yagi.
Application Number | 20090105651 11/885046 |
Document ID | / |
Family ID | 36927279 |
Filed Date | 2009-04-23 |
United States Patent
Application |
20090105651 |
Kind Code |
A1 |
Wada; Satoshi ; et
al. |
April 23, 2009 |
Puncture Device
Abstract
A puncture device is provided that does not allow an outer
needle to collapse or rise at the time of puncture and exhibits
small puncture resistance. A puncture device 1 includes: a hollow
outer needle 2; an outer needle hub 3 provided at a proximal end
portion of the outer needle 2; a hollow inner needle 4 inserted
into the outer needle 2 for use; and an inner needle hub 5 provided
at a proximal end portion of the inner needle 4. The inner needle 4
includes, from the distal side, a sharp needlepoint 41, a small
diameter portion 42 having an almost uniform outer diameter; an
intermediate portion 43 formed as a tapered portion which is
progressively increased in outer diameter as it goes toward the
proximal end; and a larger diameter portion 44 having inner and
outer diameters larger than inner and outer diameters,
respectively, of the small diameter portion 42. If the puncture
device 1 is assembled, the needlepoint 41 is most projected from
the distal opening 24 of the outer needle 2 and the proximal end of
the small diameter portion 42 and the distal end of the large
diameter portion 4 are located inside the outer needle 2. The inner
diameter of the outer needle 2 at a portion L1 where the outer
needle 2 covers the small diameter portion 42 of the inner needle 4
is smaller than the large diameter portion 44 of the inner needle
4.
Inventors: |
Wada; Satoshi; (Shizuoka,
JP) ; Soma; Katsuaki; (Shizuoka, JP) ; Yagi;
Hiroshi; (Shizuoka, JP) |
Correspondence
Address: |
BUCHANAN, INGERSOLL & ROONEY PC
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Assignee: |
Terumo Kabushiki Kaisha
Tokyo
JP
|
Family ID: |
36927279 |
Appl. No.: |
11/885046 |
Filed: |
February 16, 2006 |
PCT Filed: |
February 16, 2006 |
PCT NO: |
PCT/JP2006/302762 |
371 Date: |
July 28, 2008 |
Current U.S.
Class: |
604/164.01 |
Current CPC
Class: |
A61M 2025/0687 20130101;
A61M 25/06 20130101; A61M 25/0693 20130101; A61M 5/158
20130101 |
Class at
Publication: |
604/164.01 |
International
Class: |
A61B 17/34 20060101
A61B017/34 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 25, 2005 |
JP |
2005-050862 |
Claims
1. A puncture device comprising: a hollow outer needle; an outer
needle hub provided at a proximal end portion of the outer needle
and having a lumen portion communicating with the inside of the
outer needle; a hollow inner needle inserted into the outer needle
and having a sharp needlepoint at a distal end; and an inner needle
hub provided at a proximal end portion of the inner needle and
having a lumen portion communicating with the inside of the inner
needle; wherein the inner needle includes: a small diameter portion
located near the needlepoint and having an almost uniform outer
diameter; and a large diameter portion located closer to the
proximal end than the small diameter portion and having an outer
diameter larger than that of the small diameter portion; and
wherein if the inner needle is inserted into the lumen of the outer
needle in such a manner that the needlepoint is most projected from
the distal opening of the outer needle, the proximal end of the
small diameter portion is located in the outer needle and the inner
diameter of the outer needle at a portion where the outer needle
covers the small diameter portion is smaller than the outer
diameter of the larger diameter portion.
2. The puncture device according to claim 1, wherein the inner
diameter of the large diameter portion is greater than the inner
diameter of the small diameter portion.
3. The puncture device according to claim 1, wherein the inner
needle has an intermediate portion which is located between the
small diameter portion and the large diameter portion so as to
alleviate the changes of the outer diameters.
4. The puncture device according to claim 3, wherein the
intermediate portion is formed as a tapered portion which is
progressively increased in outer diameter as the tapered portion
goes toward the proximal end.
5. The puncture device according to claim 1, wherein if the inner
needle is inserted into the lumen of the outer needle in such a
manner that the needlepoint is most projected from the distal
opening of the outer needle, the distal end of the large diameter
portion is located inside the outer needle.
6. The puncture device according to claim 1, wherein the outer
needle includes a portion having an almost uniform outer diameter
and a tapered portion located closer to the proximal end than the
portion and progressively increased in outer diameter as the
tapered portion goes toward the proximal end.
7. The puncture device according to claim 1, wherein the outer
needle includes a reduced diameter portion which is located at a
distal end portion and is reduced in outer diameter as the reduced
diameter portion goes toward the distal end.
8. The puncture device according to claim 1, wherein the inner
diameter of the outer needle is substantially equal to or smaller
than the outer diameter of the small diameter portion of the inner
needle in a given range from the distal end.
9. The puncture device according to claim 1, wherein the inner
needle hub is formed to enable engagement with the proximal end of
the outer needle hub, and if the inner needle is inserted into the
lumen of the outer needle in such a manner that the inner hub is
engaged with the proximal end of the outer needle hub, the
needlepoint is most projected from the distal opening of the outer
needle.
10. The puncture device according to claim 1, wherein the outer
needle and the outer needle hub are integrally made of the same
material.
11. The puncture device according to claim 1, wherein if the outer
diameter (average) of the small diameter portion of the inner
needle is D1 and the outer diameter (average) of the large diameter
portion is D2, an outer diameter ratio D1/D2 is from 0.25 to
0.95.
12. The puncture device according to claim 1, wherein if the inner
diameter (average) of the small diameter portion of the inner
needle is d1 and the inner diameter (average) of the large diameter
portion is d2, an inner diameter ratio d1/d2 is from 0.2 to
0.9.
13. The puncture device according to claim 1, wherein the puncture
device is used for introducing a sheath introducer.
14. The puncture device according to claim 2, wherein the inner
needle has an intermediate portion which is located between the
small diameter portion and the large diameter portion so as to
alleviate the changes of the outer diameters.
15. The puncture device according to claim 2, wherein the outer
needle includes a portion having an almost uniform outer diameter
and a tapered portion located closer to the proximal end than the
portion and progressively increased in outer diameter as the
tapered portion goes toward the proximal end.
16. The puncture device according to claim 2, wherein the outer
needle includes a reduced diameter portion which is located at a
distal end portion and is reduced in outer diameter as the reduced
diameter portion goes toward the distal end.
17. The puncture device according to claim 2, wherein the inner
diameter of the outer needle is substantially equal to or smaller
than the outer diameter of the small diameter portion of the inner
needle in a given range from the distal end.
18. The puncture device according to claim 2, wherein the outer
needle and the outer needle hub are integrally made of the same
material.
19. The puncture device according to claim 2, wherein an outer
diameter ratio D1/D2 is from 0.25 to 0.95, where D1 represents the
outer diameter (average) of the small diameter portion of the inner
needle and D2 represents the outer diameter (average) of the large
diameter portion.
20. The puncture device according to claim 2, wherein an inner
diameter ratio d1/d2 is from 0.2 to 0.9, where d1 is the inner
diameter (average) of the small diameter portion of the inner
needle and d2 is the inner diameter (average) of the large diameter
portion.
Description
TECHNICAL FIELD
[0001] The present invention relates to a puncture device.
BACKGROUND ART
[0002] A treatment of inserting a catheter such as a balloon
catheter and a guiding catheter or a lead wire of a cardiac
pacemaker into a blood vessel is performed by using an indwelling
needle assembly (see e.g. Patent Document 1) and a sheath
introducer. The indwelling needle assembly includes an outer needle
and an inner needle inserted into the outer needle. The sheath
introducer includes a sheath and a dilator inserted into the
sheath.
[0003] In general, an indwelling needle assembly in which an outer
needle and an inner needle are assembled together (a needlepoint of
the inner needle projects from the tip of the outer needle) is
inserted into a blood vessel such as a femoral artery. The inner
needle is next withdrawn from the outer needle to indwell only the
outer needle. A guide wire is inserted into the inside of the blood
vessel through the outer needle. A sheath introducer in which a
sheath and a dilator are assembled together is inserted onto the
guide wire, introduced into the blood vessel and advanced to a
desired position. Thereafter, the dilator and the guide wire are
withdrawn to indwell the sheath in position. Thus, the inside of
the blood vessel can directly be accessed from outside of the body
of a patient through the sheath. This makes it possible to
introduce catheters of various types or the lead wire of the
cardiac pacemaker into the blood vessel via a sheath.
[0004] The indwelling needle assembly (puncture device) mentioned
above is needed to give small damage to a blood vessel at the time
of puncture and to easily catch the blood vessel. It is thus
preferred that the inner needle and the outer needle are as thin as
possible (have respective small outer diameters).
[0005] However, if a needle tube is made thin, its strength is
reduced to become yielding, deteriorating puncture performance
(accessibility of a needlepoint to a target site of a living body).
In other words, the resistance of skin, subcutaneous fat, muscle
tissue or the like deforms the needle tube, which makes it
impossible for the needlepoint to reach a targeted blood vessel. In
particular, if a puncture is made to an artery located deep in the
living body, such a defect appears dominantly and high
frequently.
[0006] The needlepoint of the inner needle which has caught the
blood vessel can be confirmed by visually observing the inflow
(flashback) of blood into an inner hub provided at the proximal end
of the inner needle. If the inner needle is made thin to reduce its
inner diameter, a time difference increases between an actual
puncture of the needlepoint into the blood vessel and the
confirmation of the flashback. This may make it probable not to
accurately and quickly recognize catch of the blood vessel.
[0007] At the time of confirming the flashback, usually the inner
needle and outer needle are slightly advanced (based on a sense or
experience of an operator, the inner and outer needles are slightly
advanced in a delicate distance). This determines that the tip of
the outer needle has been inserted into the inside of the blood
vessel. However, the late flashback has a bad influence on the
operation of advancing the inner and outer needles in a delicate
distance. For instance, the inner needle may be inserted too deep
so that it injures the opposite side of the blood vessel or impales
the blood vessel.
[0008] To quickly recognize the flashback, a puncture device 100
including an inner needle 104 with the so-called different
diameters as shown in FIG. 6 has been devised as below. The inner
needle 104 includes a small diameter portion 142, a large diameter
portion 144 and a tapered intermediate portion 143. The small
diameter portion 142 is located on the proximal end side of the
needlepoint 141. The large diameter portion 144 is located closer
to the proximal end than the small diameter portion 142 and has
inner and outer diameters greater than those of the small diameter
portion 142. The intermediate portion 143 is located between the
small diameter portion 142 and the large diameter portion 144 so as
to be formed to alleviate the changes in the inner and outer
diameters of the small and lager diameter portions 142, 144.
[0009] The puncture device 100 shown in FIG. 6 is such that the
inner needle 104 is inserted into the lumen of an outer needle 102
and a needlepoint 141 is most projected from the distal opening of
the outer needle 102. In this case, the puncture device 100 has a
significant gap between the outer needle 102 and the inner needle
104 (the small diameter portion 142) in a portion L3 where the
outer needle 102 covers the small diameter portion 142 of the inner
needle 102. The outer needle 102 easily moves on the small diameter
portion 142 of the inner needle 104; therefore, when the puncture
device 100 is inserted into skin, the outer needle 102 does not
follow the inner needle 104, which causes a phenomenon in which
only the outer needle 102 is pushed back from the surface of the
skin. If the puncture device 100 is forcibly pushed in without
change, the outer needle 102 collapses and outwardly rises at a
position close to the intermediate portion 143 of the inner needle
104, as shown in FIG. 7. After the outer needle 102 has risen, if
the puncture device 100 is further forcibly pushed in, significant
puncture resistance is produced to increase the load of the
operator and the patient.
[0010] Patent Document 1: Japanese Patent Laid-Open No.
2001-112871
DISCLOSURE OF INVENTION
Problem to be Solved by the Invention
[0011] It is an object of the present invention to provide a
puncture device that does not allow an outer needle to collapse and
rise at the time of puncture and has small puncture resistance.
Means for Solving the Problem
[0012] Such an object can be achieved by the inventions of items
(1) through (13) as below.
[0013] (1) A puncture device including: a hollow outer needle; an
outer needle hub provided at a proximal end portion of the outer
needle and having a lumen portion communicating with the inside of
the outer needle; a hollow inner needle inserted into the outer
needle and having a sharp needlepoint at a distal end; and an inner
needle hub provided at a proximal end portion of the inner needle
and having a lumen portion communicating with the inside of the
inner needle; wherein the inner needle includes: a small diameter
portion located near the needlepoint and having an almost uniform
outer diameter; and a larger diameter portion located closer to the
proximal end than the small diameter portion and having an outer
diameter larger than that of the small diameter portion; and
wherein if the inner needle is inserted into the lumen of the outer
needle in such a manner that the needlepoint is most projected from
the distal opening of the outer needle, the proximal end of the
small diameter portion is located in the outer needle and the inner
diameter of the outer needle at a portion where the outer needle
covers the small diameter portion is smaller than the outer
diameter of the larger diameter portion.
[0014] (2) The puncture device according to item (1), wherein the
inner diameter of the large diameter portion is greater than the
inner diameter of the small diameter portion.
[0015] (3) The puncture device according to item (1) or (2),
wherein the inner needle has an intermediate portion which is
located between the small diameter portion and the large diameter
portion so as to alleviate the changes of the outer diameters.
[0016] (4) The puncture device according to item (3), wherein the
intermediate portion is formed as a tapered portion which is
progressively increased in outer diameter as the tapered portion
goes toward the proximal end.
[0017] (5) The puncture device according to any one of items (1) to
(4), wherein if the inner needle is inserted into the lumen of the
outer needle in such a manner that the needlepoint is most
projected from the distal opening of the outer needle, the distal
end of the large diameter portion is located inside the outer
needle.
[0018] (6) The puncture device according to any one of items (1) to
(5), wherein the outer needle includes a portion having an almost
uniform outer diameter and a tapered portion located closer to the
proximal end than the portion and progressively increased in outer
diameter as the tapered portion goes toward the proximal end.
[0019] (7) The puncture device according to any one of items (1) to
(6) wherein the outer needle includes a reduced diameter portion
which is located at a distal end portion and is reduced in outer
diameter as the reduced diameter portion goes toward the distal
end.
[0020] (8) The puncture device according to any one of items (1) to
(7), wherein the inner diameter of the outer needle is
substantially equal to or smaller than the outer diameter of the
small diameter portion of the inner needle in a given range from
the distal end.
[0021] (9) The puncture device according to any one of items (1) to
(8), wherein the inner needle hub is formed to enable engagement
with the proximal end of the outer needle hub, and if the inner
needle is inserted into the lumen of the outer needle in such a
manner that the inner hub is engaged with the proximal end of the
outer needle hub, the needlepoint is most projected from the distal
opening of the outer needle.
[0022] (10) The puncture device according to any one of items (1)
to (9), wherein the outer needle and the outer needle hub are
integrally made of the same material.
[0023] (11) The puncture device according to any one of items (1)
to (10), wherein if the outer diameter (average) of the small
diameter portion of the inner needle is D1 and the outer diameter
(average) of the large diameter portion is D2, an outer diameter
ratio D1/D2 is from 0.25 to 0.95.
[0024] (12) The puncture device according to any one of items (1)
to (11), wherein if the inner diameter (average) of the small
diameter portion of the inner needle is d1 and the inner diameter
(average) of the large diameter portion is d2, an outer diameter
ratio d1/d2 is from 0.2 to 0.9.
[0025] (13) The puncture device according to any one of items (1)
to (12), wherein the puncture device is used for introducing a
sheath introducer.
EFFECT OF THE INVENTION
[0026] According to the invention, since an outer needle does not
collapse or rise at the time of puncture and has small puncture
resistance, each of an operator and a patient has a light load.
BRIEF DESCRIPTION OF DRAWINGS
[0027] FIG. 1 is a plan view illustrating an embodiment of a
puncture device according to the present invention.
[0028] FIG. 2 is a plan view illustrating an inner needle of the
puncture device shown in FIG. 1.
[0029] FIG. 3 is an enlarged longitudinal cross-sectional view
illustrating the periphery of the proximal end of the puncture
device shown in FIG. 1.
[0030] FIG. 4 is an enlarged longitudinal cross-sectional view
illustrating the periphery of the distal end of the puncture device
shown in FIG. 1.
[0031] FIG. 5 is a graph illustrating the relationship between
insertion amounts and resistance values in the embodiment and a
comparative example.
[0032] FIG. 6 is a plan view illustrating a conventional puncture
device.
[0033] FIG. 7 is a plan view illustrating the puncture device shown
in FIG. 6 which is inserted.
DESCRIPTION OF REFERENCE SYMBOLS
[0034] 1, 100 puncture device [0035] 2, 102 outer needle
(indwelling needle) [0036] 21 uniform outer diameter portion [0037]
22 tapered portion [0038] 23 reduced diameter portion [0039] 24
distal opening [0040] 3 outer needle hub [0041] 31 inside portion
[0042] 4, 104 inner needle [0043] 41, 141 needlepoint [0044] 42,
142 small diameter portion [0045] 43, 143 intermediate portion
[0046] 44, 144 large diameter portion [0047] 5 inner needle hub
[0048] 51 engaging portion (fitting portion) [0049] 52 inside
portion [0050] 53 finger-set portion
BEST MODE FOR CARRYING OUT THE INVENTION
[0051] A puncture device of the present invention will hereinafter
be described in detail on the basis of a preferred embodiment
illustrated in the accompanying drawings.
[0052] FIG. 1 is a plan view illustrating an embodiment of the
puncture device according to the present invention. FIG. 2 is a
plan view illustrating an inner needle of the puncture device shown
in FIG. 1. FIG. 3 is an enlarged longitudinal cross-sectional view
illustrating the periphery of the proximal end of the puncture
device shown in FIG. 1. FIG. 4 is an enlarged longitudinal
cross-sectional view illustrating the periphery of the distal end
of the puncture device shown in FIG. 1. It is to be note that the
right side and the left side in FIGS. 1 to 4 are referred to as
"the proximal end" and "the distal end", respectively, in the
following description.
[0053] Referring to FIGS. 1 through 4, the puncture device
(indwelling needle assembly) 1 of the present invention includes a
hollow outer needle 2 which is an indwelling needle (introduction
needle); and a hollow inner needle 4 which is inserted into the
outer needle 2 for use and has a sharp needlepoint 41 at its distal
end.
[0054] An outer needle hub 3 is formed integrally with the outer
needle 2 at the proximal end of the outer needle 2 and made of the
same material as the outer needle 2. The outer needle hub 3 has an
inside portion (inside space) 31 communicating with the lumen of
the outer needle 2. With this configuration, the following
advantages can be provided. The number of parts can be reduced and
manufacture is facilitated. In addition, the inner surface of a
joint between the outer needle hub 3 and the outer needle 2 can be
formed to provide a non-stepped smooth surface so that a guide wire
can smoothly be inserted into the outer needle 2.
[0055] The outer needle 2 includes a uniform outer diameter portion
21 having an almost-uniform outer diameter; and a tapered portion
22 which is progressively increased in outer diameter as it goes
toward the proximal end. Further, the outer needle 2 has a reduced
diameter portion 23 which is located at its distal end (at the
distal side of the uniform outer diameter portion 21) and is
(progressively) reduced in outer diameter as it goes toward the
distal end. The configuration described above can exhibit the
following effects: Puncture for a living body can easily be made
without impairing puncture performance (operability). In
particular, a puncture wound of a blood vessel can be made small
and puncture resistance can be made small so that invasion can be
made small at the time of the puncture. Because of the tapered
portion 22, the outer needle 2 can ensure sufficient strength
(elastic strength) so that it is prevented from being inadvertently
curvedly deformed or sharply bent. In addition, the insertion
performance of a sheath introducer can be enhanced by the tapered
portion 22 widening the puncture portion.
[0056] Referring to FIG. 4, the inner needle 4 is inserted into the
lumen of the outer needle 2 and its needlepoint 41 is most
projected from the distal opening 24 of the outer needle 2
(hereinafter, this state is called "the assembled state"). In this
case, the inner diameter of the outer needle 2 at a portion L1
where the outer needle 2 covers the small diameter portion 42 of
the inner needle 4 is smaller than the outer diameter of the large
diameter portion 44 of the inner needle 4. With the configuration
described above, the outer needle 4 is not easily moved on the
small diameter portion 42 of the inner needle 2. When the puncture
device 1 in the assembled state is inserted into a living body, the
outer needle 2 is easily inserted into the living body following
the inner needle 4 without only the outer needle 2 being pushed
back from the surface of the skin. Thus, the puncture device 1 has
advantages of small puncture resistance and of a small load on an
operator and a patient. It is to be noted that preferably such a
portion L1 has a length ranging from 1 to 30 mm and more preferably
from 3 to 10 mm.
[0057] The inner diameter of a given range L2 from the distal end
(the distal opening 24) of the outer needle 2 is substantially
equal to or slightly smaller than the outer diameter of the small
diameter portion 42 of the inner needle 4. With this configuration,
when the puncture device 1 is brought into the assembled state, the
inner circumferential surface of the distal end (the range L2) of
the outer needle 2 comes into close contact with the outer
circumferential surface of the small diameter portion 42 of the
inner needle 4. Therefore, the outer needle 2 more easily follows
the inner needle 4. In this case, a difference, in the range L2,
between the inner diameter of the outer needle 2 and the outer
diameter of the small diameter portion 42 is preferably equal to or
less than 0.05 mm, more preferably equal to or less than 0.03 mm. A
length L2 preferably ranges from 1 to 30 mm and more preferably
from 3 to 10 mm. A ratio of L2 to L1 preferably ranges from 5 to
95%, and more preferably from 20 to 80%.
[0058] A taper angle of the tapered portion 22 of the outer needle
2 (an angle of the outer surface relative to the central axis of
the outer needle 2) is not particularly restrictive but is
preferably from about 5 to about 60.degree., and more preferably
from about 15 to about 25.degree.. Such taper angles allow both the
tapered portion 22 to ensure sufficient strength and a living
tissue to be widened with small puncture resistance.
[0059] The outer diameter and inner diameter of the distal end of
the tapered portion 22 are almost equal to the outer diameter and
inner diameter, respectively, of the proximal end of the uniform
outer diameter portion 21. With this configuration, the outer
surface of a boundary portion between the tapered portion 22 and
the uniform outer diameter portion 21 becomes a non-stepped smooth
surface. Thus, a living tissue such as a skin can be widened while
minimizing the puncture resistance of the outer needle 2.
[0060] In addition, the inner surface of a boundary portion between
the tapered portion 22 and the uniform outer diameter portion 21
becomes a non-stepped smooth surface. Thus, when inserted into the
outer needle 2, the guide wire can smoothly be inserted thereinto
without being caught.
[0061] Preferably, the outer diameter and inner diameter of the
proximal end of the tapered portion 22 are substantially equal to
the outer diameter and inner diameter, respectively, of the distal
end of the outer needle hub 3. With this configuration, the inner
surface of a boundary portion between the tapered portion 22 and
the outer needle hub 3 becomes a non-stepped smooth surface. Thus,
when inserted into the outer needle 2, the guide wire can smoothly
be inserted thereinto without being caught.
[0062] Since the outer needle 2 is provided with the tapered
portion 22 as described above, the tapered portion 22 exhibits a
function of widening a living tissue such as skin when the outer
needle 2 is inserted into a living body. Consequently, an effect
can be provided that insertion resistance encountered when a sheath
introducer is inserted is reduced.
[0063] The length of the uniform outer diameter portion 21 is not
particularly restrictive but is preferably from about 5 to about
100 mm, and more preferably from about 15 to about 60 mm.
[0064] The outer diameter (average) of the uniform outer diameter
portion 21 is not particularly restrictive but is preferably from
about 0.6 to about 2.2 mm, and more preferably from about 1.0 to
about 1.8 mm.
[0065] The wall thickness of a tube of the uniform outer diameter
portion 21 is not particularly restrictive. However, the wall
thickness is preferably from about 0.05 to about 0.30 mm, and more
preferably from about 0.10 to 0.20 mm, in order not to hinder the
outer needle 2 from being reduced in diameter while ensuring
sufficient strength.
[0066] The length of the taper portion 22 is not restrictive but is
preferably from about 3 to about 50 mm, and more preferably from
about 5 to about 10 mm.
[0067] The maximum outer diameter of the tapered portion (the outer
diameter of the proximal end of the tapered portion 22) is not
particularly restrictive but is preferably from about 4.0 to about
8.0 mm, and more preferably from about 5.0 to about 6.0 mm.
[0068] The wall thickness of the tube of the tapered portion 22 is
not particularly restrictive. However, the wall thickness is
preferably from about 0.2 to about 2.0 mm, and more preferably from
about 0.5 to about 1.0 mm, in order not to hinder the outer needle
2 from being reduced in diameter while ensuring sufficient
strength.
[0069] The length of the reduced diameter portion 23 is not
particularly restrictive and is preferably from about 0.2 to about
30 mm, and more preferably from about 1 to about 10 mm.
[0070] The wall thickness of a tube of the most distal end (the
neighborhood of the distal opening 24) of the reduced diameter
portion 23 is preferably 0.05 mm or less, and more preferably from
about 0.01 to about 0.001 mm, in order to reduce a step difference
between the outer surface of the inner needle 4 and the distal end
of the reduced diameter portion 23.
[0071] The constituent material of the outer needle 2 is not
particularly restrictive. However, examples of the preferable resin
material include: fluorine series resins such as
polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene
copolymer (ETFE), polyethylene propylene-fluoride (FEP), poly
perfluoro alkoxy resin (PFA), and polyvinylidene-fluoride resin
(PVDF); polyolefin such as polyethylene, polypropylene and
polybutylene; polyamide, polyester, polyurethane, polyether-nylon
resin. The constituent material of the outer needle 2 may be
blended with an X-ray contrast agent such as barium sulfate and
barium carbonate to provide a contrast radiography function.
[0072] The outer needle 2 described above can be manufactured by
e.g., injection molding, extrusion molding, blow molding, heating
drawing or other methods.
[0073] The outer needle 2 is preferably formed to be longitudinally
dividable into a plurality of parts (e.g., two parts). With this
configuration, the outer needle 2 can easily be removed with a
medical device such as a guide wire indwelled within the body by
dividing and removing the outer needle 2 with the medical device
inserted therein.
[0074] Examples of a configuration of making the outer needle 2
dividable include providing fragile portions (not shown) which are
formed of two or more groove portions extending along the
longitudinal direction of the outer needle 2.
[0075] Referring to FIG. 3, an inner needle hub 5 (housing) formed
of an almost cylindrical member is liquid-sealingly joined to the
proximal end of the inner needle 4. The inside portion (inside
space) 52 of the inner needle hub 5 communicates with the lumen of
the inner needle 4. Preferably, the inner needle hub 5 is formed of
a transparent or semi-transparent resin to ensure the visibility of
the inside portion 52. With this configuration, the needlepoint 41
which has caught the blood vessel can be confirmed by visually
observing flashback.
[0076] A diameter reduced engaging portion (fitting portion) 51 is
formed at the distal end of the inner needle hub 5. In the
assembled state, the engaging portion 51 is engaged with (fitted
into) the proximal end of the outer needle hub 3 (see FIG. 3). In
the assembled state where the outer needle hub 3 is engaged with
the inner needle hub 5, the needlepoint 41 of the inner needle 4 is
most projected from the distal opening 24 of the outer needle
2.
[0077] A flange-like finger-set portion 53 is formed on the
distal-side outer circumferential portion of the inner needle hub
5.
[0078] An aeration filter (not shown) may be attached to the
proximal end of the inner needle hub 5 so as to seal the proximal
opening of the inner needle hub 5. The aeration filter passes gas
but cannot pass liquid. With this configuration, the blood that has
passed through the inner needle 4 and flown in the inside portion
52 of the inner needle hub 5 is prevented from leaking from the
proximal opening of the inner needle hub 5. The aeration filter has
sufficient aeration property before coming into contact with blood;
therefore, a time taken for the flashback can be reduced.
[0079] Specific examples of such an aeration filter include
sintered porous bodies, hydrophobic nonwoven material and other
porous bodies. In this case, a preferable example of the sintered
porous bodies includes a sintered material containing polymer
material (powder) such as polyethylene and hydrophilic
(water-soluble, water-swellable) polymer. The sintered porous body
interrupts aeration because of contact with liquid (blood);
therefore, air can be prevented from entering from the outside.
[0080] The inner needle 4 is made of a metal material such as
stainless steel, aluminum, an aluminum alloy, titanium and a
titanium alloy. The inner needle 4 is formed with the sharp
needlepoint 41 at its distal end. The needlepoint 41 has a pair of
blade surfaces inclined at a given angle relative to the axis of
the inner needle 4.
[0081] As shown in FIGS. 2 and 4, the inner needle 4 includes the
small diameter portion 42 and the larger diameter portion 44. The
small diameter portion 42 is located near the proximal end of the
needlepoint 41 and has an almost uniform outer diameter. The large
diameter portion 44 is located closer to the proximal end than the
small diameter portion 42 and has an inner diameter and an outer
diameter larger than the inner diameter and outer diameter,
respectively, of the small diameter portion 42. In addition, the
inner needle 4 has the intermediate portion 43 which is located
between the small diameter portion 42 and the large diameter
portion 44 to alleviate the changes (differences in the outer
diameters) of the outer diameters thereof. The intermediate portion
43 is formed of a tapered portion which is progressively increased
in outer diameter as it goes toward the proximal end.
[0082] With this configuration, puncture for a living body can
easily be made without impairing puncture performance
(operability). In particular, a puncture wound of a blood vessel
can be made small and puncture resistance can be made small so that
invasion can be made small at the time of the puncture. A risk of
damaging the tissues of a blood vessel, a nerve, a muscle other
than the puncture wound can also be reduced. Since the inner
diameter of the inner needle is increased from its mid-portion
because of the large diameter portion 44, the flow of the blood in
the inner needle 4 is promoted to reduce a time taken for the
flashback (a time taken for the blood flowing in from the
needlepoint 41 to reach the inside of the inner needle hub 5).
Thus, it is possible to quickly and reliably recognize that the
needlepoint 41 has caught the blood vessel. Because of having the
large diameter portion 44, the inner needle 4 ensures sufficient
strength (elastic strength) so that it is prevented from being
inadvertently curvedly deformed or sharply bent at the time of the
puncture or the like.
[0083] The large diameter portion 44 may have an almost uniform
outer diameter over the full length thereof or may have a tapered
portion at, at least, a portion thereof in the longitudinal
direction, the tapered portion being progressively increased in
outer diameter as it goes toward the proximal end. Alternatively,
the large diameter portion may be formed stepwise to have two or
more portions different from each other in outer diameter.
[0084] As shown in FIG. 4, in the assembled state, the intermediate
portion (the tapered portion) 43 of the inner needle 4 is located
inside the outer needle 2. That is to say, the distal end of the
large diameter portion 44 of the inner needle 4 is located inside
the outer needle 4 and also the proximal end of the small diameter
portion 42 on the distal side of the large diameter 44 is located
inside the outer needle 4.
[0085] The length of the needlepoint 41 is not particularly
restrictive but is preferably from about 0.5 to about 5.0 mm, and
more preferably from about 1.0 to about 3.5 mm.
[0086] The length of the small diameter portion 42 is not
particularly restrictive but is preferably from about 1 to about 30
mm, and more preferably from about 2 to about 15 mm.
[0087] The outer diameter (average) D1 of the small diameter
portion 42 is not particularly restrictive but is preferably from
about 0.25 to about 1.7 mm and more preferably from about 0.5 to
about 1.0 mm.
[0088] The inner diameter (average) d1 of the small diameter
portion 42 is not particularly restrictive but is preferably from
about 0.1 to about 1.5 mm, and more preferably from about 0.3 to
about 0.6 mm.
[0089] The length of the tapered portion 43 is not particularly
restrictive but is preferably from about 0.5 to about 10 mm, and
more preferably from about 1 to about 3.5 mm.
[0090] The length of the large diameter portion 44 is not
particularly restrictive but is preferably from about 10 to about
200 mm and more preferably from about 25 to about 80 mm.
[0091] The outer diameter (average) D2 of the large diameter
portion 44 is not particularly restrictive but is preferably from
about 0.4 to about 2.0 mm and more preferably from about 0.6 to
about 1.3 mm.
[0092] The inner diameter (average) d2 of the large diameter
portion 44 is not particularly restrictive but is preferably from
about 0.2 to about 1.8 mm and more preferably from about 0.4 to
about 1.1 mm.
[0093] Such dimensions described above can provide a satisfactory
balance between the strength and puncture performance of the inner
needle 4. In particular, the inner needle 4 will not be overcome
with the puncture resistance to otherwise bend; therefore, an
effect of excellent puncture performance becomes prominent.
[0094] The outer diameter ratio D1/D2 is preferably from about 0.25
to about 0.95 and more preferably from about to about 0.8. The
outer diameter ratio set within such a range allows the inner
needle 4 to provide more satisfactory puncture performance while
ensuring sufficient strength.
[0095] The inner diameter ratio d1/d2 is preferably from about 0.2
to about 0.9 and more preferably from about 0.5 to about 0.8. The
inner diameter ratio set within such a range can more reduce a time
taken for flashback while allowing the inner needle 4 to ensure
sufficient strength and satisfactory puncture performance.
[0096] Such an inner needle 4 can be manufactured by a method
employing one of or a combination of two or more of plastic
processing such as press work, swaging, and drawing, cutting,
polishing, laser machining, and etching.
[0097] Examples of the constituent material for the inner needle
hub 5 include: polyolefin such as polyethylene, polypropylene,
ethylene-vinyl acetate copolymer; polyvinyl chloride;
polymethylmethacrylate; polycarbonate; polybutadiene; polyamide;
polyester such as polyethylene terephthalate, polybutylene
terephthalate; acrylic resins; ABS resins; ionomer; polyacetal;
polyphenylene sulfide; polyether ether ketone.
[0098] A description is next made of how to use the puncture device
1 (of how the puncture device 1 is operated) by way of example.
[0099] [1] As shown in FIG. 1, the outer needle 2 and the inner
needle 4 are assembled together in advance. In such an assembled
state, the needlepoint 41 most projects from the distal opening 24
of the outer needle 2 and the proximal end of the small diameter
portion 42 and the distal end of the large diameter portion 44 are
accommodated inside the outer needle 2.
[0100] [2] The inner needle 4 and outer needle 2 in the assembled
state are percutaneously inserted into to a blood vessel (a vein or
artery) of a patient.
[0101] When the needlepoint 41 of the inner needle 4 is inserted
into the blood vessel, blood flows into the inner needle 4 from the
opening of the needlepoint 41 due to the inside pressure in the
blood vessel (blood pressure), back-flowing toward the proximal end
of the inner needle 4, and is introduced into the inside portion 52
of the inner needle hub 5. The flashback can be visualized in the
hub 5 having visibility. Thus, it can be recognized that the
needlepoint 41 of the inner needle 4 has caught the blood
vessel.
[0102] [3] When a finger is set on the finger-set portion 53 to fix
the inner needle hub 5 and the outer needle hub 3 and the outer
needle 2 are advanced toward the distal end in a minute distance,
the distal end of the outer needle 2 is inserted into the blood
vessel. Thus, the distal end portion of the outer needle 2 catches
the blood vessel.
[0103] [4] While the outer needle 2 remains indwelled, the inner
needle hub 5 is drawn toward the proximal end to withdraw the inner
needle 4 from the outer needle 2.
[0104] [5] The guide wire (not shown) is inserted into the
indwelled outer needle 2 from the proximal opening of the outer
needle hub 3. When the distal end of the guide wire reaches inside
the blood vessel, the outer needle 2 is withdrawn.
[0105] [6] After a sheath introducer in which a dilator is inserted
into a sheath is prepared, the sheath introducer is inserted into a
living body through the guide wire. When the distal end of the
sheath introducer is introduced into the blood vessel, the guide
wire and dilator are withdrawn to leave (indwell) the sheath, which
catches the blood vessel.
[0106] [7] For instance, one of various catheters or a lead wire of
a cardiac pacemaker is introduced into the blood vessel via the
indwelled sheath implanted.
[0107] Incidentally, the application use and usage of the puncture
device 1 of the present invention are not limited to the above. For
example, after the above process [4], an infusion line is connected
to the outer needle hub 3 via a connector. An infusion is fed
through the infusion line to the patient for administration.
[0108] The puncture device of the present invention has been
described thus far with reference to the embodiment illustrated in
the drawings. The present invention is not limited to the
embodiment described above. The members constituting the puncture
device can be replaced with optional constituent members that can
exhibit the same respective functions or may be added with
respective optional constructions. For instance, an outer needle
hub made of a material different from that of the outer needle may
be fixedly attached to the proximal end of the outer needle in a
liquid-sealed manner.
EXAMPLES
[0109] A description is next made of a specific example of the
puncture device of the present invention.
[0110] The puncture device shown in FIGS. 1 to 4 was manufactured.
The dimensions of the puncture device are as follows:
[0111] The outer diameter of the small diameter portion 42 of the
inner needle 4: 0.90 mm
[0112] The length of the small diameter portion 42 of the inner
needle 4: 6 mm
[0113] The length of the intermediate portion 43 of the inner
needle 4: 3 mm
[0114] The outer diameter of the large diameter portion 44 of the
inner needle 4: 1.25 mm
[0115] The length (L2) of a portion of the outer needle 2 in close
contact with the small diameter portion 44 of the inner needle 4: 5
mm
[0116] The inner diameter of the outer needle 2 at a portion
corresponding to the boundary portion between the small diameter
portion 42 and intermediate portion 43 of the inner needle 4: 0.98
mm
[0117] The inner diameter of the outer needle 2 at a portion
corresponding to the large diameter portion of the inner needle 4:
1.30 mm
[0118] Next, the puncture device was inserted at 20 mm deep into
cattle hide with a thickness of 1 mm at an angle of 45.degree. and
the resistance values relative to the respective puncture distances
(insertion amounts) were determined. FIG. 5 shows the results.
[0119] FIG. 5 shows that the maximum resistance value is 343 gf.
Collapse or rise of the outer needle was not particularly found
after 20-mm-deep insertion.
Comparative Example
[0120] The puncture device of FIG. 6 was manufactured. The
dimensions of the puncture device are as follows:
[0121] The outer diameter of the small diameter portion 142 of the
inner needle 104: 0.90 mm
[0122] The length of the small diameter portion 142 of the inner
needle 104: 6 mm
[0123] The length of the intermediate portion 143 of the inner
needle 104: 3 mm
[0124] The outer diameter of the large diameter portion 144 of the
inner needle 104: 1.25 mm
[0125] The length of a portion of the outer needle 102 in close
contact with the small diameter portion 144 of the inner needle
104: 1 mm
[0126] The inner diameter of the outer needle 102 at a portion
corresponding to the boundary portion between the small diameter
portion 142 and intermediate portion 143 of the inner needle 104:
1.30 mm
[0127] The inner diameter of the outer needle 102 at a portion
corresponding to the large diameter portion of the inner needle
104: 1.30 mm
[0128] Next, the resistance values relative to the respective
puncture distances (insertion amounts) were determined in the same
manner as those of the embodiment. FIG. 5 shows the results.
[0129] FIG. 5 shows that the maximum resistance value is 454 gf,
which is about 1.3 times greater than that of the embodiment. Rise
of the outer needle was found after 20-mm-deep insertion.
* * * * *